Post processing of low cost Aligners fabricated by additive manufacturing process to enhance the surface quality and...

Area of Science:

• Materials Science and Engineering
• Biomedical Engineering
• Manufacturing Technology

Background:

• Additive Manufacturing (AM) offers advantages like mass customization but suffers from staircase effects, degrading surface quality.
• Fused Deposition Modeling (FDM) is a cost-effective method for producing clear aligners from biocompatible PETG.
• Poor surface quality of FDM-fabricated aligners is a significant challenge for clinical application.

Purpose of the Study:

• To develop and evaluate a Chemical Vapor Smoothing (CVS) method for improving the surface quality of FDM-fabricated PETG clear aligners.
• To compare the effectiveness of different smoothing chemicals (methylethylketone, toluene, cyclohexanone) on surface roughness.
• To analyze the influence of process parameters on surface quality using Response Surface Methodology (RSM).

Main Methods:

• A novel experimental setup was designed for Chemical Vapor Smoothing (CVS).
• Surface roughness (Ra) was measured to quantify surface quality improvements.
• Response Surface Methodology (RSM) was employed to analyze process parameters: chemical volume, exposure time, and workpiece orientation.

Main Results:

• Cyclohexanone demonstrated superior performance, achieving a 92.73% reduction in surface roughness.
• Methylethylketone and toluene resulted in 89.66% and 88.63% reductions, respectively.
• Workpiece orientation was identified as the most impactful parameter affecting surface roughness reduction during CVS.

Conclusions:

• Chemical Vapor Smoothing is an effective method for enhancing the surface quality of FDM-printed PETG clear aligners.
• Cyclohexanone is the most effective chemical for achieving uniform and smooth surfaces.
• The developed CVS process significantly improves the aesthetic and functional qualities of 3D-printed dental aligners.